JW Pharmaceutical’s Hemlibra improves young hemophilia patients’ joint health

JW Pharmaceutical said Monday that interim results from a long-term study of Hemlibra (emicizumab) in children with severe non-antibody hemophilia A confirmed that the drug improved joint health in patients.

Hemlibra is a breakthrough medicine that mimics factor 8, a blood clotting factor deficient in the bodies of people with hemophilia A. It uses bispecific antibody technology that binds to factors 9 and 10. Hemlibra is the only treatment for hemophilia A that can be used in antibody and non-antibody patients resistant to existing treatments (factor 8 agents). It provides long-lasting prophylaxis with subcutaneous injections once every four weeks.

Professor Midori Shima and colleagues at Nara University in Japan are studying 30 non-antibody patients with severe hemophilia A under 12 who were previously treated with factor 8. The team, which has been evaluating Hemlibra's efficacy and impact on joint health since 2019, presented interim results data at the recent American Society of Hematology (ASH) 2023 Annual Meeting (ASH 2023) at about three years (Week 145).

The interim results showed that the number of patients experiencing synovial hypertrophy, an enlargement of the lubricating membrane that facilitates joint movement, and hemosiderin, a darkening of the skin due to the deposition of hemosiderin pigment in the blood, decreased from 10 patients at Week 1 to two patients at Week 145.

In addition, the Hemophilia Joint Health Score (HJHS) improved from 0.90 at Week 1 to 0.44 at Week 145. The HJHS measures joint health in people with hemophilia; the more severe the joint damage, the higher the score.

The average annualized bleed rate (ABR) decreased from 3.7 pre-HEMLIBRA to 0.7 post-HEMLIBRA, and the frequency of joint bleeding requiring treatment improved from 0.4 to 0.2.

"Recurrent joint bleeding can lead to hemophilic arthropathy, which can lead to chronic pain," a JW Pharmaceutical official said. "It is significant that this study confirms that Hemlibra is effective in improving joint health in children with severe hemophilia A."